/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors 
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.hisp.dhis.webapi.view;

import jakarta.servlet.http.HttpServletRequest;
import java.util.Locale;
import java.util.Map;
import org.apache.commons.lang3.StringUtils;
import org.springframework.http.MediaType;
import org.springframework.web.accept.PathExtensionContentNegotiationStrategy;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.util.UrlPathHelper;

/**
 * Custom PathExtensionContentNegotiationStrategy that handles multiple dots in filename. Based on:
 * org.springframework.web.accept.PathExtensionContentNegotiationStrategy
 * org.springframework.util.StringUtils
 *
 * @author Morten Olav Hansen <mortenoh@gmail.com>
 */
public class CustomPathExtensionContentNegotiationStrategy
    extends PathExtensionContentNegotiationStrategy {
  private static final UrlPathHelper URL_PATH_HELPER = new UrlPathHelper();

  private static final char EXTENSION_SEPARATOR = '.';

  private static final String FOLDER_SEPARATOR = "/";

  static {
    URL_PATH_HELPER.setUrlDecode(false);
  }

  public CustomPathExtensionContentNegotiationStrategy(Map<String, MediaType> mediaTypes) {
    super(mediaTypes);
  }

  @Override
  protected String getMediaTypeKey(NativeWebRequest webRequest) {
    HttpServletRequest servletRequest = webRequest.getNativeRequest(HttpServletRequest.class);

    if (servletRequest == null) {
      return null;
    }

    String path = URL_PATH_HELPER.getLookupPathForRequest(servletRequest);
    String extension = getFilenameExtension(path);

    return !StringUtils.isBlank(extension) ? extension.toLowerCase(Locale.ENGLISH) : null;
  }

  private static String getFilenameExtension(String path) {
    if (path == null) {
      return null;
    }
    int extIndex = path.indexOf(EXTENSION_SEPARATOR);

    if (extIndex == -1) {
      return null;
    }

    int folderIndex = path.indexOf(FOLDER_SEPARATOR);

    if (folderIndex > extIndex) {
      return null;
    }

    return path.substring(extIndex + 1);
  }
}
